Power regulation for a microelectronic device such as a microprocessor must include a steady voltage along a predetermined load line and an ability to respond to dynamic current demands of the processor. For example, as a microprocessor executes instructions, particularly at faster rates, severe power transients and widely varying current requirements are likely to occur. Buck converters have been advantageously utilized to meet the power demands of microprocessors; which typically require very high currents at very low voltages.
A regulator located at or near the load can improve the precision of regulated power provided to the load. Point of load (POL) regulators are well known. In the cross-referenced patent applications, various power regulators have been disclosed. However, in some applications, more than one regulator is required because one regulator cannot provide the large amount of current required either as a steady-state or as a transient response. A problem with utilizing multiple regulators is the inefficiency that occurs when various regulators provide different levels of current to the load.
In the multi-phase regulators disclosed, for example in MULTI-THRESHOLD MULTI-GAIN ACTIVE TRANSIENT RESPONSE CIRCUIT AND METHOD FOR DIGITAL MULTIPHASE PULSE WIDTH MODULATED REGULATORS, Ser. No. 10/938,031, filed Sep. 10, 2004, inventors Tang et al. and DIGITAL CALIBRATION WITH LOSSLESS SENSING IN A MULTIPHASE SWITCHED POWER CONVERTER, Ser. No. 10/884,840, filed Jul. 2, 2004, inventors: Southwell et al, the balancing of current among the phases could be achieved by controlling the output of the pulse widths supplied by the multi-phase pulse width modulators. However, the problem of balancing the output of multiple multi-phase (or single phase) regulators was not described.